re: bathroom sink leak on new installation -picture included-

Hello there,
I am have a leak on a new bathroom sink I have just installed at my relatives' place.
It occurs just below the slip/jamb nut, but above the pivot rod assembly.

In the picture, the threads appear white (because there is teflon tape on them. I forgot to teflon tape the entire thread, as there is no tape under the slip/jamb nut or above it). You can see the water droplet in the red square box where the leak is occuring.

I used the foam gasket that came with the fixtures. I wonder if that could be the culprit.

The question is, what is the best course of action? Tighten the slip nut? or disassemble all drain components and retighten/retape / apply plumber's puddy in place of the foam gasket that is under the flange.
other action??

The water sometimes follows the threads.
I use either pipe dope or putty on the threads where the large rubber washer is supposed to seal. That prevents the water from following the threads past the large foam washer.

If you just wrapped tape after the fact...well just don't do that. But as others explained, and you can see in your pic, water will literally travel down along the threads and appear. The rubber gasket cannot bite into the threads deep enough. So we pack the threads with putty ( some use silicone) then slide up the mack washer and the nut.

I wouldn't trust plumber's putty. Keep the foam in place and use thread compound. What I do is after hand tightening is wrap a loop of string around it and pull as if I was to strangle it, to press it tighter to the pipe. Tighten some more and repeat.

The plumbers have been using plumbers putty successfully for years.
I sometimes use the foam washer that is supplied for the flange,
Most of the time, like 95% I use putty, that is unless the basin is marble or stone.

Ugh, I hate those 3-piece tailpiece units...they can be a bit aggravating at times. Heavily pipe doping the threads above the friction washer will certainly seal this up, but so will applying tape to just the right spot. I suspect that part of the problem is that you are not tightening the nut tight enough. If all else fails, buy yourself a real 1-piece unit and be done with it!

The lav drain is a "special case". It is not pipe thread, so pipe dope or tape is not the best solution. And putty would NOT be used if we were trying to make the threads do the seal. But in this case, the threads are only used to send the nut up which clamps the gasket against the bottom of the sink. THAT seal works fine, but the mack gasket is usually stiff enough that it does not "bite" into the threads, and a droplet of water will wind its way down around the threads and out the bottom. Using your thumb to fill up the threads in effect creates a uniform smooth surface, and the gasket DOES seal up against that.

If there were any pressure at all, this would not work. But for THIS application, putty in the threads is an age-old procedure. Older than me, as far as I know!

We have been installing those for years...probably 50+ years in the case of Redwood, Wheelchair, and hj. WHEN they make a better design, we'll let you know!

Click to expand...

Sorry, that's not what i meant.
If someone today asks you to replace your drain because the chrome is all scratched off some part below is rusted through or leaky beyond repair, what brand and model# replacement do you use...today. is that brand model# easy to install?
(when I said future, I meant if it happens in my future what do I choose)